The pathogenicity and acute toxicity of Lactobacillus (L.) pentosus PL11 from eel (Anguilla japonica) were investigated using male and female Sprague-Dawley rats. The pathogenicity of L. pentosus PL11 was examined after treating the rats with 10∨11 CFU/mL, 10∨9 CFU/mL or 10∨7 CFU/mL doses of L. pentosus PL11 culture or 0.85% NaCl (Control) intragastrically. For acute toxicity studies, rats were treated with dried culture broth of L. pentosus PL11 at doses of 5,000 mg/mL, 2,500 mg/mL, 1,250 mg/mL or 625 mg/mL or Lactobacilli MRS broth (Control), and clinical signs or mortalities were monitored for two weeks. The results of the present investigation revealed no mortalities or obvious clinical signs in rats administered with the live bacterial cultures or dried culture broth at any investigated dose level. Also, no significant differences were observed in net body weight gain, gross pathological findings, feed and water consumption and body temperature among the different treatment groups and between the treated and control rats. It can be concluded from the above findings that L. pentosus PL11 is a safe probiotic strain with potential as feed additive to increase the feed efficiency or health of fish.

The present study was carried out to investigate the potential acute toxicity of CKD-602 by a single intravenous dose in Beagle dogs. The test chemical was administered intravenously to male and female Beagle dogs at dose levels of 0.3, 0.5, or 2.5 mg/kg. Mortalities, clinical findings, and body weight changes were monitored for the 14-day period following the administration. At the end of 14-day observation period, all animals were sacrificed and complete gross postmortem examinations were performed. All males and females of the 2.5 mg/kg dose group were found dead between the fourth and seventh day after the injection.

Investigation of acute and subchronic (chronic) toxicity of complexinates of trace elements in experiments with calves was realized in the conditions of the Republic of Belarus. The realized experiments were based on developed in Belarus veterinary preparations for the treatment and prevention of diseases connected with disorders of trace elements exchange containing chelate compounds of trace elements with sodium ethylene diamine acetate: Cuprovet (on the basis of CuNa); Cobalvet (on the basis of CoNa), Zinkovet (on the basis of ZnNa), and Feravet (on the basis of FeNa). There were the following indexes of ferrum in nephros - 55,3 +/- 2,26, in muscles - 134 +/- 26,6 mkg/g, and in liver - 565 +/- 35,5 mkg/g after administration of Feravet. There were the following index of zinc in nephros - 56,3 +/- 2,64, in muscles -25, 8 +/- 1,23 and in liver - 84,4 +/- 3,29 mkg/g after administration of Zinkovet. There were the following indexes of cuprum in nephros - 4,1 +/- 0,325, in muscles - 2,33 +/- 0,117, and in liver - 12,3 +/- 1,12 mkg/g after administration of Cuprovet. There were the following indexes of cobalt in nephros - 40,35 +/- 2,29, in muscles - 12,5 +/- 0,98, and in liver - 126,5 +/- 10,45 ng/g after administration of Cobalvet. Parameters of toxicity of all preparations were by the example of laboratory mice, rats and calves given. Content of trace elements in blood of calves in dynamics of the experiment was analyzed. There were determined parameters of acute toxicity of the analyzed preparations: they all could be referred to substance hazard category 4 (low-hazardous substances). The determined parameters of acute toxicity made it possible to recommend them for treatment and prophylaxis of microelementoses of cattle, as well as to use them as feed additives taking into consideration that defect action levels of the analysed preparations exceed the deficiency needs of cattle in case of their limited cumulation

Evaluation of safety and efficiency of application of immunostimulative drug Izambenum (C14H15IN2O) for stimulation of natural resistance (autarcesis) and immunologic responsiveness of chickens of laying breeds was realized in the conditions of the Republic of Belarus. Clinical and experimental investigation of Izambenum influence on poultry for the increasing of their resistance, activation of immunological response to vaccination against Newcastle disease, stimulation of their growth and development was realized. Research results showed that Izambenum influenced on level of morphological indexes of chicken blood: number of erythrocytes increased on 24%, hemoglobin - on 17%. Total protein in blood serum increased in all test period and number of lymphocytes increased and differential was 90-100%. Izambenum increased strains of post vaccination immunity to Newcastle disease. Bacterial growth-inhibitory activity decreased on the 27the day of life and increased at the same positions on the 34-41 days. Phagocyte activity of pseudoeosinophils increased in all test groups. Research results showed that Izambenum rendered growth and immunity stimulation action and increased their viability. Its immunostimulative action was conditioned by strengthening of cellular and to lower extent humoral immunity factors. Application of the preparation in period of Newcastle disease vaccination promoted the formation of long-lived immunity

Investigation of acute sub-acute toxicity of preparative forms (herbal infusion, tincture liquid extract and pulvis) of marsh cinquefoil (Comarum palustre) by the example of laboratory animals was realized in the conditions of the Republic of Belarus. White mice of both sexes with body weight of 18-20 g and white rats with body weight of 180-200 g were used in the experiment. Experimental preparations were administrated on empty stomach after 12 hours of absolute diet. The animals were supervised in course of 14 days. All changes in behavior were registered. Calculations of parameters of acute and average toxicity of all analyzed forms were presented. Research results showed that all analyzed preparative forms could be referred to the substances hazard category 4 (low-hazardous substances) with lethal dose 50 more than 5000 mg/kg of live weight. It was determined that the analyzed preparative forms proved to be highly effective against strongylatosis (Strongylata) of gastro-intestinal tract of sheep and calves

Results of studies of acute and chronic toxicity of control samples of long acting boluses on the basis of fenbendazole for the treatment of strongylatosis (Strongylata) of gastro-intestinal tract of cattle realized in the conditions of the Republic of Belarus were presented. White rats and mice were used for studying of acute and chronic toxicity of the prolonged anthelmintic. The preparation was tested in doses of 400; 800; 1200; 1600; and 2000 mg/kg of body weight. Prolonged anthelmintic was administrated introgastrally in the form of suspension. Preparation was reduced to fragments before application. White rats with body weight of 80-100 g were divided in three groups and were used for testing. Bolus of prolonged activity was reduced to fragments and mixed with feed before application. Rats ate the preparation during 30 day in dozes of 250 mg/kg, 375 mg/kg, and 500 mg/kg. Study of acute toxicity of preparation established that LD0 for white mice was 400 mg/kg; LD16 - 620 mg/kg; LD50 - 1080 (1062,7 / 1097, 3) mg/kg; LD84 - 1660, LD100 - 200 mg/kg. Signs of animal toxicosis were revealed in shakiness, depression, whiteness of visually accessible mucous coat, cramps. Catarrhal-haemorrhagic gastroenteritis and numerous effusions of blood on mucous coat of digestive tract were established at postmortem examination. There were no morphological changes in tissues of lungs, heart, liver and nephros. Eating of prolonged anthelmintic with feed during 30 days did not render toxicological influence on rats. There were no signs of intoxication, physiological deviations and no animal death. Research results showed that the analyzed prolonged anthelmintic could be referred the substance hazard category 3

Studying of toxicity of enterosorbent produced the basis of mixture of filtering pulvis of perlite, kizelgur and activated carbon was realized in the conditions of the Republic of Belarus by the example of healthy white mice of both sexes with body weight of 18-25 grams. Animals were divided in three groups. The tested substance was entered insitu to ventricle on an empty stomach after 12-hours of absolute diet. The first group animals were administrated the enterosorbent in doze of 5 g/1 kg, the second group animals - 2,5 g/1 kg. Glucose content increased from 3,8 +/- 0,47 to 4,3 +/- 0,17 mmol/l on the 30-th experimental day and decreased on 8,2 % on the 60-th experimental day. Cholesterin and triglyceride content lowered on 9,5 % and 11,1 %,respectively. Enzymes concentration of aspartate transaminase and alkaline phosphatase decreased from 120,0 +/- 3,87 up to 117,0 +/- 2,58 units/l and from 396,3 +/- 3,78 to 345,3 +/- 2,97 units/l, respectively. Urea increased from 3,7 +/- 0,16 to 3,9 +/- 0,17 mmol/l on the 30-th experimental day. Research results showed that mixture of filtering pulvis after the single oral administration in dose of 2,5-5 g/1 kg did not cause mice death. The analyzed mixture could be referred to the class of low-toxic substances. The mixture did not have irritation action and did not render chronic toxic action on the experimental mice